search for: hmm_device_entry_from_pfn

...ap(pfn, pgmap); > + if (unlikely(!pgmap)) > return -EBUSY; Unrelated to this patch, but what is the point of getting checking that the pgmap exists for the page and then immediately releasing it? This code has this pattern in several places. It feels racy > } > pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags; > } > - if (hmm_vma_walk->pgmap) { > - put_dev_pagemap(hmm_vma_walk->pgmap); > - hmm_vma_walk->pgmap = NULL; Putting the value in the hmm_vma_walk would have made some sense to me if the pgmap was not set to NULL all over the place. Then the most x...

...If it's the former case, validating ZONE_DEVICE pfns, I imagine we can do something cheaper with a helper that is on the order of the same cost as pfn_valid(). I.e. replace PTE_DEVMAP with a mem_section flag or something similar. > > > } > > pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags; > > } > > - if (hmm_vma_walk->pgmap) { > > - put_dev_pagemap(hmm_vma_walk->pgmap); > > - hmm_vma_walk->pgmap = NULL; > > Putting the value in the hmm_vma_walk would have made some sense to me > if t...

...ddr; return hmm_pfns_fill(addr, end, range, HMM_PFN_NONE); } @@ -207,7 +206,6 @@ static int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr, pfn = pmd_pfn(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags; - hmm_vma_walk->last = end; return 0; } #else /* CONFIG_TRANSPARENT_HUGEPAGE */ @@ -386,13 +384,10 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp, r = hmm_vma_handle_pte(walk, addr, end, pmdp, ptep, pfns); if (r) { /* hmm_vma_handle_pte() did pte_unmap() */ -...

...ddr; return hmm_pfns_fill(addr, end, range, HMM_PFN_NONE); } @@ -207,7 +206,6 @@ static int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr, pfn = pmd_pfn(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags; - hmm_vma_walk->last = end; return 0; } #else /* CONFIG_TRANSPARENT_HUGEPAGE */ @@ -386,13 +384,10 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp, r = hmm_vma_handle_pte(walk, addr, end, pmdp, ptep, pfns); if (r) { /* hmm_vma_handle_pte() did pte_unmap() */ -...

...pfns[i]); + page = hmm_device_entry_to_page(range, range->pfns[i]); if (page == NULL) continue; diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 3457cf9182e5..9799fde71f2e 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -290,42 +290,6 @@ static inline uint64_t hmm_device_entry_from_pfn(const struct hmm_range *range, range->flags[HMM_PFN_VALID]; } -/* - * Old API: - * hmm_pfn_to_page() - * hmm_pfn_to_pfn() - * hmm_pfn_from_page() - * hmm_pfn_from_pfn() - * - * This are the OLD API please use new API, it is here to avoid cross-tree - * merge painfullness ie we convert thin...

...pfns[i]); + page = hmm_device_entry_to_page(range, range->pfns[i]); if (page == NULL) continue; diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 657606f48796..cdcd78627393 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -290,40 +290,6 @@ static inline uint64_t hmm_device_entry_from_pfn(const struct hmm_range *range, range->flags[HMM_PFN_VALID]; } -/* - * Old API: - * hmm_pfn_to_page() - * hmm_pfn_to_pfn() - * hmm_pfn_from_page() - * hmm_pfn_from_pfn() - * - * This are the OLD API please use new API, it is here to avoid cross-tree - * merge painfullness ie we convert thin...

...re good we will work with only a single pagemap, so it makes some sense to cache it once we find it? diff --git a/mm/hmm.c b/mm/hmm.c index 9a908902e4cc38..4e30128c23a505 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -497,10 +497,6 @@ static int hmm_vma_handle_pmd(struct mm_walk *walk, } pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags; } - if (hmm_vma_walk->pgmap) { - put_dev_pagemap(hmm_vma_walk->pgmap); - hmm_vma_walk->pgmap = NULL; - } hmm_vma_walk->last = end; return 0; #else @@ -604,10 +600,6 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, return 0;...

...hift); -} - /* * Please see Documentation/vm/hmm.rst for how to use the range API. */ diff --git a/mm/hmm.c b/mm/hmm.c index 2693393dc14b30..c1c96d4cc0554c 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -37,28 +37,13 @@ enum { HMM_NEED_ALL_BITS = HMM_NEED_FAULT | HMM_NEED_WRITE_FAULT, }; -/* - * hmm_device_entry_from_pfn() - create a valid device entry value from pfn - * @range: range use to encode HMM pfn value - * @pfn: pfn value for which to create the device entry - * Return: valid device entry for the pfn - */ -static uint64_t hmm_device_entry_from_pfn(const struct hmm_range *range, - unsigned long pfn)...

...hift); -} - /* * Please see Documentation/vm/hmm.rst for how to use the range API. */ diff --git a/mm/hmm.c b/mm/hmm.c index 2e975eedb14f89..41673a6d8d46d1 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -37,28 +37,13 @@ enum { HMM_NEED_ALL_BITS = HMM_NEED_FAULT | HMM_NEED_WRITE_FAULT, }; -/* - * hmm_device_entry_from_pfn() - create a valid device entry value from pfn - * @range: range use to encode HMM pfn value - * @pfn: pfn value for which to create the device entry - * Return: valid device entry for the pfn - */ -static uint64_t hmm_device_entry_from_pfn(const struct hmm_range *range, - unsigned long pfn)...

From: Jason Gunthorpe <jgg at mellanox.com> The API is a bit complicated for the uses we actually have, and disucssions for simplifying have come up a number of times. This small series removes the customizable pfn format and simplifies the return code of hmm_range_fault() All the drivers are adjusted to process in the simplified format. I would appreciated tested-by's for the two

...for how to use the range API. > */ > diff --git a/mm/hmm.c b/mm/hmm.c > index 2693393dc14b30..c1c96d4cc0554c 100644 > --- a/mm/hmm.c > +++ b/mm/hmm.c > @@ -37,28 +37,13 @@ enum { > HMM_NEED_ALL_BITS = HMM_NEED_FAULT | HMM_NEED_WRITE_FAULT, > }; > > -/* > - * hmm_device_entry_from_pfn() - create a valid device entry value from pfn > - * @range: range use to encode HMM pfn value > - * @pfn: pfn value for which to create the device entry > - * Return: valid device entry for the pfn > - */ > -static uint64_t hmm_device_entry_from_pfn(const struct hmm_range *range, &g...

...end; addr += PAGE_SIZE, i++, pfn++) { if (pmd_devmap(pmd)) { - hmm_vma_walk->pgmap = get_dev_pagemap(pfn, - hmm_vma_walk->pgmap); - if (unlikely(!hmm_vma_walk->pgmap)) + pgmap = get_dev_pagemap(pfn, pgmap); + if (unlikely(!pgmap)) return -EBUSY; } pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags; } - if (hmm_vma_walk->pgmap) { - put_dev_pagemap(hmm_vma_walk->pgmap); - hmm_vma_walk->pgmap = NULL; - } + if (pgmap) + put_dev_pagemap(pgmap); hmm_vma_walk->last = end; return 0; #else @@ -520,7 +517,7 @@ static inline uint64_t pte_to_hmm_pfn_flags(st...

On Tue, Aug 13, 2019 at 06:36:33PM -0700, Dan Williams wrote: > Section alignment constraints somewhat save us here. The only example > I can think of a PMD not containing a uniform pgmap association for > each pte is the case when the pgmap overlaps normal dram, i.e. shares > the same 'struct memory_section' for a given span. Otherwise, distinct > pgmaps arrange to manage

Hi Jérôme, Ben and Jason, below is a series against the hmm tree which fixes up the mmap_sem locking in nouveau and while at it also removes leftover legacy HMM APIs only used by nouveau.

Hi Jérôme, Ben, Felix and Jason, below is a series against the hmm tree which cleans up various minor bits and allows HMM_MIRROR to be built on all architectures. Diffstat: 11 files changed, 94 insertions(+), 210 deletions(-) A git tree is also available at: git://git.infradead.org/users/hch/misc.git hmm-cleanups.2 Gitweb:

From: Jason Gunthorpe <jgg at mellanox.com> The API is a bit complicated for the uses we actually have, and disucssions for simplifying have come up a number of times. This small series removes the customizable pfn format and simplifies the return code of hmm_range_fault() All the drivers are adjusted to process in the simplified format. I would appreciated tested-by's for the two

...int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, goto unlock; } - pfn = pte_pfn(entry) + ((start & mask) >> PAGE_SHIFT); + pfn = pte_pfn(entry) + ((start & hmask) >> PAGE_SHIFT); for (; addr < end; addr += PAGE_SIZE, i++, pfn++) range->pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags; -- 2.20.1

...int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, goto unlock; } - pfn = pte_pfn(entry) + ((start & mask) >> PAGE_SHIFT); + pfn = pte_pfn(entry) + ((start & ~hmask) >> PAGE_SHIFT); for (; addr < end; addr += PAGE_SIZE, i++, pfn++) range->pfns[i] = hmm_device_entry_from_pfn(range, pfn) | cpu_flags; -- 2.20.1

...c int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, return -EBUSY; } else if (IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) && pte_special(pte)) { *pfn = range->values[HMM_PFN_SPECIAL]; - return -EFAULT; + return is_zero_pfn(pte_pfn(pte)) ? 0 : -EFAULT; } *pfn = hmm_device_entry_from_pfn(range, pte_pfn(pte)) | cpu_flags; -- 2.20.1

...-254,7 +262,7 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, * Never fault in device private pages pages, but just report * the PFN even if not present. */ - if (is_device_private_entry(entry)) { + if (hmm_is_device_private_entry(range, entry)) { *pfn = hmm_device_entry_from_pfn(range, swp_offset(entry)); *pfn |= range->flags[HMM_PFN_VALID]; -- 2.24.1